NFC: add the NFC socket raw protocol
Lauro Ramos Venancio [Fri, 1 Jul 2011 22:31:36 +0000 (19:31 -0300)]
This socket protocol is used to perform data exchange with NFC
targets.

Signed-off-by: Lauro Ramos Venancio <lauro.venancio@openbossa.org>
Signed-off-by: Aloisio Almeida Jr <aloisio.almeida@openbossa.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

include/linux/nfc.h
net/nfc/Makefile
net/nfc/core.c
net/nfc/nfc.h
net/nfc/rawsock.c [new file with mode: 0644]

index 15f8cb3..330a4c5 100644 (file)
@@ -24,6 +24,9 @@
 #ifndef __LINUX_NFC_H
 #define __LINUX_NFC_H
 
+#include <linux/types.h>
+#include <linux/socket.h>
+
 #define NFC_GENL_NAME "nfc"
 #define NFC_GENL_VERSION 1
 
@@ -109,7 +112,15 @@ enum nfc_attrs {
 #define NFC_PROTO_ISO14443_MASK        (1 << NFC_PROTO_ISO14443)
 #define NFC_PROTO_NFC_DEP_MASK (1 << NFC_PROTO_NFC_DEP)
 
+struct sockaddr_nfc {
+       sa_family_t sa_family;
+       __u32 dev_idx;
+       __u32 target_idx;
+       __u32 nfc_protocol;
+};
+
 /* NFC socket protocols */
-#define NFC_SOCKPROTO_MAX      0
+#define NFC_SOCKPROTO_RAW      0
+#define NFC_SOCKPROTO_MAX      1
 
 #endif /*__LINUX_NFC_H */
index e081fdb..16250c3 100644 (file)
@@ -4,4 +4,4 @@
 
 obj-$(CONFIG_NFC) += nfc.o
 
-nfc-objs := core.o netlink.o af_nfc.o
+nfc-objs := core.o netlink.o af_nfc.o rawsock.o
index e804dc5..b6fd4e1 100644 (file)
@@ -432,6 +432,10 @@ static int __init nfc_init(void)
        /* the first generation must not be 0 */
        nfc_devlist_generation = 1;
 
+       rc = rawsock_init();
+       if (rc)
+               goto err_rawsock;
+
        rc = af_nfc_init();
        if (rc)
                goto err_af_nfc;
@@ -439,6 +443,8 @@ static int __init nfc_init(void)
        return 0;
 
 err_af_nfc:
+       rawsock_exit();
+err_rawsock:
        nfc_genl_exit();
 err_genl:
        class_unregister(&nfc_class);
@@ -448,6 +454,7 @@ err_genl:
 static void __exit nfc_exit(void)
 {
        af_nfc_exit();
+       rawsock_exit();
        nfc_genl_exit();
        class_unregister(&nfc_class);
 }
index 8335f4d..aaf9832 100644 (file)
@@ -42,6 +42,20 @@ struct nfc_protocol {
                        const struct nfc_protocol *nfc_proto);
 };
 
+struct nfc_rawsock {
+       struct sock sk;
+       struct nfc_dev *dev;
+       u32 target_idx;
+       struct work_struct tx_work;
+       bool tx_work_scheduled;
+};
+#define nfc_rawsock(sk) ((struct nfc_rawsock *) sk)
+#define to_rawsock_sk(_tx_work) \
+       ((struct sock *) container_of(_tx_work, struct nfc_rawsock, tx_work))
+
+int __init rawsock_init(void);
+void rawsock_exit(void);
+
 int __init af_nfc_init(void);
 void af_nfc_exit(void);
 int nfc_proto_register(const struct nfc_protocol *nfc_proto);
diff --git a/net/nfc/rawsock.c b/net/nfc/rawsock.c
new file mode 100644 (file)
index 0000000..52de84a
--- /dev/null
@@ -0,0 +1,354 @@
+/*
+ * Copyright (C) 2011 Instituto Nokia de Tecnologia
+ *
+ * Authors:
+ *    Aloisio Almeida Jr <aloisio.almeida@openbossa.org>
+ *    Lauro Ramos Venancio <lauro.venancio@openbossa.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the
+ * Free Software Foundation, Inc.,
+ * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#include <net/tcp_states.h>
+#include <linux/nfc.h>
+
+#include "nfc.h"
+
+static void rawsock_write_queue_purge(struct sock *sk)
+{
+       nfc_dbg("sk=%p", sk);
+
+       spin_lock_bh(&sk->sk_write_queue.lock);
+       __skb_queue_purge(&sk->sk_write_queue);
+       nfc_rawsock(sk)->tx_work_scheduled = false;
+       spin_unlock_bh(&sk->sk_write_queue.lock);
+}
+
+static void rawsock_report_error(struct sock *sk, int err)
+{
+       nfc_dbg("sk=%p err=%d", sk, err);
+
+       sk->sk_shutdown = SHUTDOWN_MASK;
+       sk->sk_err = -err;
+       sk->sk_error_report(sk);
+
+       rawsock_write_queue_purge(sk);
+}
+
+static int rawsock_release(struct socket *sock)
+{
+       struct sock *sk = sock->sk;
+
+       nfc_dbg("sock=%p", sock);
+
+       sock_orphan(sk);
+       sock_put(sk);
+
+       return 0;
+}
+
+static int rawsock_connect(struct socket *sock, struct sockaddr *_addr,
+                                                       int len, int flags)
+{
+       struct sock *sk = sock->sk;
+       struct sockaddr_nfc *addr = (struct sockaddr_nfc *)_addr;
+       struct nfc_dev *dev;
+       int rc = 0;
+
+       nfc_dbg("sock=%p sk=%p flags=%d", sock, sk, flags);
+
+       if (!addr || len < sizeof(struct sockaddr_nfc) ||
+               addr->sa_family != AF_NFC)
+               return -EINVAL;
+
+       nfc_dbg("addr dev_idx=%u target_idx=%u protocol=%u", addr->dev_idx,
+                                       addr->target_idx, addr->nfc_protocol);
+
+       lock_sock(sk);
+
+       if (sock->state == SS_CONNECTED) {
+               rc = -EISCONN;
+               goto error;
+       }
+
+       dev = nfc_get_device(addr->dev_idx);
+       if (!dev) {
+               rc = -ENODEV;
+               goto error;
+       }
+
+       if (addr->target_idx > dev->target_idx - 1 ||
+               addr->target_idx < dev->target_idx - dev->n_targets) {
+               rc = -EINVAL;
+               goto error;
+       }
+
+       if (addr->target_idx > dev->target_idx - 1 ||
+               addr->target_idx < dev->target_idx - dev->n_targets) {
+               rc = -EINVAL;
+               goto error;
+       }
+
+       rc = nfc_activate_target(dev, addr->target_idx, addr->nfc_protocol);
+       if (rc)
+               goto put_dev;
+
+       nfc_rawsock(sk)->dev = dev;
+       nfc_rawsock(sk)->target_idx = addr->target_idx;
+       sock->state = SS_CONNECTED;
+       sk->sk_state = TCP_ESTABLISHED;
+       sk->sk_state_change(sk);
+
+       release_sock(sk);
+       return 0;
+
+put_dev:
+       nfc_put_device(dev);
+error:
+       release_sock(sk);
+       return rc;
+}
+
+static int rawsock_add_header(struct sk_buff *skb)
+{
+
+       if (skb_cow_head(skb, 1))
+               return -ENOMEM;
+
+       *skb_push(skb, 1) = 0;
+
+       return 0;
+}
+
+static void rawsock_data_exchange_complete(void *context, struct sk_buff *skb,
+                                                               int err)
+{
+       struct sock *sk = (struct sock *) context;
+
+       BUG_ON(in_irq());
+
+       nfc_dbg("sk=%p err=%d", sk, err);
+
+       if (err)
+               goto error;
+
+       err = rawsock_add_header(skb);
+       if (err)
+               goto error;
+
+       err = sock_queue_rcv_skb(sk, skb);
+       if (err)
+               goto error;
+
+       spin_lock_bh(&sk->sk_write_queue.lock);
+       if (!skb_queue_empty(&sk->sk_write_queue))
+               schedule_work(&nfc_rawsock(sk)->tx_work);
+       else
+               nfc_rawsock(sk)->tx_work_scheduled = false;
+       spin_unlock_bh(&sk->sk_write_queue.lock);
+
+       sock_put(sk);
+       return;
+
+error:
+       rawsock_report_error(sk, err);
+       sock_put(sk);
+}
+
+static void rawsock_tx_work(struct work_struct *work)
+{
+       struct sock *sk = to_rawsock_sk(work);
+       struct nfc_dev *dev = nfc_rawsock(sk)->dev;
+       u32 target_idx = nfc_rawsock(sk)->target_idx;
+       struct sk_buff *skb;
+       int rc;
+
+       nfc_dbg("sk=%p target_idx=%u", sk, target_idx);
+
+       if (sk->sk_shutdown & SEND_SHUTDOWN) {
+               rawsock_write_queue_purge(sk);
+               return;
+       }
+
+       skb = skb_dequeue(&sk->sk_write_queue);
+
+       sock_hold(sk);
+       rc = nfc_data_exchange(dev, target_idx, skb,
+                               rawsock_data_exchange_complete, sk);
+       if (rc) {
+               rawsock_report_error(sk, rc);
+               sock_put(sk);
+       }
+}
+
+static int rawsock_sendmsg(struct kiocb *iocb, struct socket *sock,
+                                       struct msghdr *msg, size_t len)
+{
+       struct sock *sk = sock->sk;
+       struct sk_buff *skb;
+       int rc;
+
+       nfc_dbg("sock=%p sk=%p len=%zu", sock, sk, len);
+
+       if (msg->msg_namelen)
+               return -EOPNOTSUPP;
+
+       if (sock->state != SS_CONNECTED)
+               return -ENOTCONN;
+
+       skb = sock_alloc_send_skb(sk, len, msg->msg_flags & MSG_DONTWAIT,
+                                                                       &rc);
+       if (!skb)
+               return rc;
+
+       rc = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
+       if (rc < 0) {
+               kfree_skb(skb);
+               return rc;
+       }
+
+       spin_lock_bh(&sk->sk_write_queue.lock);
+       __skb_queue_tail(&sk->sk_write_queue, skb);
+       if (!nfc_rawsock(sk)->tx_work_scheduled) {
+               schedule_work(&nfc_rawsock(sk)->tx_work);
+               nfc_rawsock(sk)->tx_work_scheduled = true;
+       }
+       spin_unlock_bh(&sk->sk_write_queue.lock);
+
+       return len;
+}
+
+static int rawsock_recvmsg(struct kiocb *iocb, struct socket *sock,
+                               struct msghdr *msg, size_t len, int flags)
+{
+       int noblock = flags & MSG_DONTWAIT;
+       struct sock *sk = sock->sk;
+       struct sk_buff *skb;
+       int copied;
+       int rc;
+
+       nfc_dbg("sock=%p sk=%p len=%zu flags=%d", sock, sk, len, flags);
+
+       skb = skb_recv_datagram(sk, flags, noblock, &rc);
+       if (!skb)
+               return rc;
+
+       msg->msg_namelen = 0;
+
+       copied = skb->len;
+       if (len < copied) {
+               msg->msg_flags |= MSG_TRUNC;
+               copied = len;
+       }
+
+       rc = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
+
+       skb_free_datagram(sk, skb);
+
+       return rc ? : copied;
+}
+
+
+static const struct proto_ops rawsock_ops = {
+       .family         = PF_NFC,
+       .owner          = THIS_MODULE,
+       .release        = rawsock_release,
+       .bind           = sock_no_bind,
+       .connect        = rawsock_connect,
+       .socketpair     = sock_no_socketpair,
+       .accept         = sock_no_accept,
+       .getname        = sock_no_getname,
+       .poll           = datagram_poll,
+       .ioctl          = sock_no_ioctl,
+       .listen         = sock_no_listen,
+       .shutdown       = sock_no_shutdown,
+       .setsockopt     = sock_no_setsockopt,
+       .getsockopt     = sock_no_getsockopt,
+       .sendmsg        = rawsock_sendmsg,
+       .recvmsg        = rawsock_recvmsg,
+       .mmap           = sock_no_mmap,
+};
+
+static void rawsock_destruct(struct sock *sk)
+{
+       nfc_dbg("sk=%p", sk);
+
+       if (sk->sk_state == TCP_ESTABLISHED) {
+               nfc_deactivate_target(nfc_rawsock(sk)->dev,
+                                       nfc_rawsock(sk)->target_idx);
+               nfc_put_device(nfc_rawsock(sk)->dev);
+       }
+
+       skb_queue_purge(&sk->sk_receive_queue);
+
+       if (!sock_flag(sk, SOCK_DEAD)) {
+               nfc_err("Freeing alive NFC raw socket %p", sk);
+               return;
+       }
+}
+
+static int rawsock_create(struct net *net, struct socket *sock,
+                               const struct nfc_protocol *nfc_proto)
+{
+       struct sock *sk;
+
+       nfc_dbg("sock=%p", sock);
+
+       if (sock->type != SOCK_SEQPACKET)
+               return -ESOCKTNOSUPPORT;
+
+       sock->ops = &rawsock_ops;
+
+       sk = sk_alloc(net, PF_NFC, GFP_KERNEL, nfc_proto->proto);
+       if (!sk)
+               return -ENOMEM;
+
+       sock_init_data(sock, sk);
+       sk->sk_protocol = nfc_proto->id;
+       sk->sk_destruct = rawsock_destruct;
+       sock->state = SS_UNCONNECTED;
+
+       INIT_WORK(&nfc_rawsock(sk)->tx_work, rawsock_tx_work);
+       nfc_rawsock(sk)->tx_work_scheduled = false;
+
+       return 0;
+}
+
+static struct proto rawsock_proto = {
+       .name     = "NFC_RAW",
+       .owner    = THIS_MODULE,
+       .obj_size = sizeof(struct nfc_rawsock),
+};
+
+static const struct nfc_protocol rawsock_nfc_proto = {
+       .id       = NFC_SOCKPROTO_RAW,
+       .proto    = &rawsock_proto,
+       .owner    = THIS_MODULE,
+       .create   = rawsock_create
+};
+
+int __init rawsock_init(void)
+{
+       int rc;
+
+       rc = nfc_proto_register(&rawsock_nfc_proto);
+
+       return rc;
+}
+
+void rawsock_exit(void)
+{
+       nfc_proto_unregister(&rawsock_nfc_proto);
+}